Distal endoscope part having light emitting source such as light emitting diodes as illuminating means

ABSTRACT

A substrate having a plurality of light emitting diodes united therewith lies on a plane containing the longitudinal axis of an insertion unit of an endoscope and its neighborhood. Likewise, part of a first objective surface lies on the plane containing the longitudinal axis of the insertion unit of the endoscope and its neighborhood. As long as the diameter of the insertion unit remains unchanged, the plane containing the longitudinal axis of the insertion unit of the endoscope and its neighborhood provides the largest area for the light emitting diodes. The light emitting diode sub-assembly is therefore placed on the plane, whereby the outer diameter of a distal endoscope part can be made as small as possible.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a distal endoscope part, or moreparticularly, a distal endoscope part characterized by a portion thereofin which light emitting diodes serving as an illuminating means areplaced.

[0003] 2. Description of the Related Art

[0004] Structures having a light emitting source such as light emittingdiodes incorporated as an illuminating means in a distal endoscope parthave been proposed in the past.

[0005] For example, Japanese Unexamined Patent Publication No. 63-260526describes a distal endoscope part for side viewing in which a pluralityof light emitting diodes is placed circumferentially with an objectiveoptical system as a center in order to improve the light emittingcharacteristic of the distal part.

[0006] However, according to the related art (Japanese Unexamined PatentPublication No. 63-260526), the light emitting diodes are placed on aspherical surface on the outer circumference of an endoscope. Theplurality of light emitting diodes must be attached one by one to adistal member.

[0007] When the light emitting diodes must be attached one by one to thedistal endoscope member, there is difficulty in narrowing the spacingbetween adjoining light emitting diodes. A side viewing endoscope havinga plurality of light emitting diodes placed on the outer circumferenceof an objective optical system has a drawback that the distal partthereof is large in size.

[0008] Moreover, Japanese Unexamined Patent Publication No. 8-117184 hasproposed a structure having a light emitting source as an illuminatingmeans incorporated in a distal endoscope part. Japanese Utility ModelRegistration No. 3007137 has proposed a structure having light emittingdiodes as an illuminating means placed around a camera in a distal partof a tubular examination camera system. In these structures, the lightemitting unit is protected with a cover glass or acrylic plate placed onthe front surface thereof.

[0009] Especially in the Japanese Utility Model Registration No.3007137, the cover glass over the front surfaces of the light emittingdiodes also works to leave the light emitting diodes watertight.

[0010] However, when a watertight structure is realized using atransparent member such as the cover glass as it is as described in therelated art, the cover glass must have a thickness large enough toposition the perimeter thereof relative to a metallic member and supportit. In the structure having the cover glass, therefore, mechanicalmembers must be made larger by a dimension corresponding to theperimeter used for positioning.

[0011] As described in the Japanese Utility Model Registration No.3007137, a structure has the light emitting diodes, which serves as anilluminating means, placed on the outer circumference of an imaging unitand a transparent member placed on the front surfaces of the lightemitting diodes. This poses a problem in that the outer diameter of thedistal part must be made larger by a dimension corresponding to theperimeter of the transparent member.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to provide a distalendoscope part making it possible to realize a side viewing endoscopehaving a plurality of light emitting diodes placed on the outercircumference of an objective optical system without an increase in theouter diameter of the distal part.

[0013] Another object of the present invention is to provide a distalendoscope part making it possible to realize a watertight structurewithout the necessities of placing a transparent member over the frontsurfaces of light emitting diodes and of increasing the outer diameterof the distal part.

[0014] A distal endoscope part in accordance with the present inventionhas a plurality of light emitting diodes for supplying illuminationlight placed as an illuminating means on the outer circumference of anobjective optical system. The plurality of light emitting diodes ismounted on a substrate and united therewith. A sub-assembly of theplurality of united light emitting diodes is placed on a planecontaining the longitudinal axis of an insertion unit of an endoscopeand its neighborhood. Consequently, although the side viewing endoscopehas the plurality of light emitting diodes placed on the outercircumference of the objective optical system, the outer diameter of thedistal part thereof is not large in size.

[0015] Other features of the present invention and advantages thereofwill be fully apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 to FIG. 10 relate to the first embodiment of the presentinvention;

[0017]FIG. 1 shows the configuration of a side viewing endoscope;

[0018]FIG. 2 is a longitudinal sectional view showing the structure of adistal endoscope part shown in FIG. 1;

[0019]FIG. 3 is a cross sectional view of the A-A plane of the distalendoscope part shown in FIG. 2;

[0020]FIG. 4 is a top view of the distal endoscope part shown in FIG. 2;

[0021]FIG. 5 is a longitudinal sectional view showing the BB plane ofthe distal endoscope part shown in FIG. 4;

[0022]FIG. 6 is a cross sectional view showing the C-C plane of thedistal endoscope part shown in FIG. 2;

[0023]FIG. 7 is a first explanatory diagram for explaining a firstvariant of the distal endoscope part shown in FIG. 1;

[0024]FIG. 8 is a second explanatory diagram for explaining the firstvariant of the distal endoscope part shown in FIG. 1;

[0025]FIG. 9 is a first explanatory diagram for explaining a secondvariant of the distal endoscope part shown in FIG. 1;

[0026]FIG. 10 is a second explanatory diagram for explaining a secondvariant of the distal endoscope part shown in FIG. 1;

[0027]FIG. 11 to FIG. 21 relate to the second embodiment of the presentinvention;

[0028]FIG. 11 shows the configuration of a side viewing endoscope;

[0029]FIG. 12 is a longitudinal sectional view showing the structure ofthe distal endoscope part shown in FIG. 11;

[0030]FIG. 13 is a cross sectional view showing the A-A plane of thedistal endoscope part shown in FIG. 12;

[0031]FIG. 14 is a top view of the distal endoscope part shown in FIG.12;

[0032]FIG. 15 is a longitudinal sectional view showing the B-B plane ofthe distal endoscope part shown in FIG. 12;

[0033]FIG. 16 is a cross sectional view showing the C-C plane of thedistal endoscope part shown in FIG. 12;

[0034]FIG. 17 is a cross sectional view showing the D-D plane of thedistal endoscope part shown in FIG. 12;

[0035]FIG. 18 is a cross sectional view showing the E-E plane of thedistal endoscope part shown in FIG. 12;

[0036]FIG. 19 is a longitudinal sectional view showing the structure ofa control unit included in the distal endoscope part shown in FIG. 11;

[0037]FIG. 20 shows the structure of a variant of the control unit shownin FIG. 19;

[0038]FIG. 21 shows the structure of a light emitting diode included inthe distal endoscope part shown in FIG. 14;

[0039]FIG. 22 to FIG. 24 relate to the third embodiment of the presentinvention;

[0040]FIG. 22 is a longitudinal sectional view showing the structure ofa distal endoscope part;

[0041]FIG. 23 is a cross sectional view showing the F-F plane of thedistal endoscope part shown in FIG. 22; and

[0042]FIG. 24 is a cross sectional view showing the G-G plane of thedistal endoscope part shown in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] First Embodiment

[0044] As shown in FIG. 1, a side viewing endoscope 1 has an insertionunit 2 to be inserted into an intracorporeal cavity. A distal endoscopepart (hereinafter referred to as a distal part) in accordance with thepresent invention attached to the distal end of the insertion unit 2includes an imaging means and light emitting diodes serving as anilluminating means. A control unit attached to the proximal end of theinsertion unit 2 has a light level adjustment knob 5 used to adjust anamount of light emitted from the light emitting diodes in the distalpart 3.

[0045] An optical image of an object illuminated the light emittingdiodes is projected on an imaging unit included in the distal part 3,and converted into an electric signal. The electric signal is sent to acamera control unit 7 over a camera control cable 6. Image datarepresented by the electric signal is processed by the camera controlunit 7 that is powered by an AC adapter 8. An image signal produced bythe camera control unit 7 is transferred to a monitor 10 over a monitorcable 9. An endoscopic image is then displayed.

[0046] As shown in FIG. 2 and FIG. 3, an imaging unit 13 for convertingan optical signal into an electric signal is fixed to a body 15 with aholder 14 between them by means of screws 16. The imaging unit 13consists of a solid-state imaging device 11 and electronic parts 12.

[0047] An objective sub-assembly 17 for converging an optical image atthe solid-state imaging device 11 is placed ahead of the solid-stateimaging device 11. The optical image represents an object located in adirection of side viewing (at a right angle with respect to thelongitudinal direction of the insertion unit 2).

[0048] A signal cable 18 over which a signal is transferred from thecamera control unit 7 to the imaging unit 13, and power cables 20 overwhich power is supplied to the light emitting diodes 19 serving as anilluminating means are passed through the insertion unit 2.

[0049] As shown in FIG. 4 to FIG. 6, the light emitting diodes 19serving as an illuminating means for irradiating illumination light inthe direction of side viewing (at a right angle with respect to thelongitudinal direction of the insertion unit 2) are soldered to asubstrate 21. The power cables 20 are also soldered to the substrate 21.The substrate 21 having the light emitting diodes and power cablesunited therewith is fixed to a body 22 by means of screws A 23.

[0050] The substrate 21 having the plurality of light emitting diodes 19united therewith lies on a plane containing the longitudinal axis 25 ofthe insertion unit and its neighborhood.

[0051] Likewise, part of a first objective surface 30 lies on the planecontaining the longitudinal axis 25 of the insertion unit of theendoscope and its neighborhood. As long as the outer diameter of theendoscope remains unchanged, the plane containing the longitudinal axis25 of the insertion unit and its neighborhood provides the largest areafor the light emitting diodes. If the light emitting diode sub-assembly19 is placed on the plane, the outer diameter of the distal part 3 canbe made as small as possible.

[0052] The light emitting diodes 19 are fixed to the body 22 togetherwith the substrate 21. Thereafter, a substantially transparent filler 24is injected to fully cover the surroundings of the light emitting diodes19 and the light emitting surfaces thereof. Even the tops of the lightemitting diodes 19 are covered with the filler 24, whereby the lightemitting diodes 19 are not only protected to be blocked from outside butalso left watertight.

[0053] The light emitting diodes 19 on the substrate 21 may be, as shownin FIG. 7 and FIG. 8, mounted in pairs. In this case, the sub-assemblyof the light emitting diodes mounted on the substrate 21 is attached toa distal mechanical member 32. Paired light emitting diodes 19 cantherefore be located mutually as closely as possible. Consequently, thewidth 33 of the substrate can be decreased and the outer diameter of thedistal part can be minimized.

[0054] Moreover, as shown in FIG. 9 and FIG. 10, a package for eachlight emitting diode 19 may be shaped like a sector in order to improvethe density of mounted components and the efficiency in emitting light.

[0055] As mentioned above, according to the present embodiment, thesubstrate 21 having the plurality of light emitting diodes 19 unitedtherewith is placed on the plane containing the longitudinal axis 25 ofthe insertion unit and its neighborhood. Part of the first objectivesurface 30 is also placed on the plane containing the longitudinal axis25 of the insertion unit and its neighborhood. As long as the outerdiameter of the endoscope remains unchanged, the plane containing thelongitudinal axis 25 of the insertion unit and its neighborhood canprovide the largest area for the light emitting diodes. For this reason,the outer diameter of the distal part 3 can be minimized.

[0056] In other words, the light emitting diode sub-assembly made bymounting the plurality of light emitting diodes on the substrate isplaced on the plane containing the longitudinal axis 25 of the insertionunit and its neighborhood. Therefore, the density of mounted componentscan be improved and the outer diameter of the distal endoscope part canbe minimized.

[0057] Moreover, the plurality of light emitting diodes can be assembledat a time. This leads to easy assembling.

[0058] Second Embodiment

[0059] As shown in FIG. 11, a side viewing endoscope 101 has aninsertion unit 102 that is inserted into an intracorporeal cavity. Adistal endoscope part 103 (hereinafter referred to as a distal part) inaccordance with the present embodiment attached to the distal end of theinsertion unit 102 has an imaging means and light emitting diodesserving as an illuminating means. A control unit 104 attached to theproximal end of the insertion unit 102 has a light level adjustment knob105 used to adjust an amount of light emitted from the light emittingdiodes in the distal part 103.

[0060] An optical image of an object illuminated by the light emittingdiodes is projected on an imaging unit in the distal part 103, andconverted into an electric signal. The electric signal is sent to acamera control unit 107 over a camera control cable 106. Image datarepresented by the electric signal is processed by the camera controlunit 107 that is powered by an AC adapter 108. An image signal producedby the camera control unit 107 is transferred to a monitor 110 over amonitor cable 109. Consequently, an endoscopic image is displayed.

[0061] As shown in FIG. 12 and FIG. 13, an imaging unit 113 forconverting an optical signal to an electric signal is fixed to a body115 in the distal part 103 with a holder 114 between them by means ofscrews C 116. The imaging unit 113 consists of a solid-state imagingdevice 111 and electronic parts 112.

[0062] Moreover, an objective sub-assembly 117 for converging an opticalimage at the solid-state imaging device 111 is located ahead of thesolid-state imaging device 111. The optical image represents an objectlocated in a direction of side viewing (at a right angle with respect tothe longitudinal direction of the insertion unit 2).

[0063] A signal cable 118 over which a signal is transferred from thecamera control unit 107 to the imaging unit 113, and power cables 120over which power is supplied to the light emitting diodes 119 are passedthrough the insertion unit 102. The light emitting diodes 119 serve asan illuminating means and will be described later.

[0064] As shown in FIG. 14 and FIG. 15, the light emitting diodes 119serving as an illuminating means for irradiating illumination light inthe direction of side viewing (at a right angle with respect to thelongitudinal direction of the insertion unit 102) are soldered to asubstrate 121. The power cables 120 are also soldered to the substrate121. The substrate 121 having the light emitting diodes and power cablesunited therewith is fixed to a body 122 by means of screws A 123.

[0065] The light emitting diodes 119 are fixed to the body 122 togetherwith the substrate 121. Thereafter, a substantially transparent filler124 is injected to fully cover the surroundings of the light emittingdiodes 119 including the light emitting surfaces thereof. Even the topsof the light emitting diodes 119 are covered with the filler 124,whereby the light emitting diodes 119 are not only protected to beblocked from outside but also left watertight.

[0066] As shown in FIG. 16 and FIG. 17, the body 115 and body 122 aresecured by a screw B 125. Part of a lens frame 127 mounted on the outercircumference of an objective 126 located behind a prism and included inthe objective sub-assembly 117 is notched. This is because the dimensionbetween the objective 126 and the body 115 that is a mate member is notlarge enough to tolerate the thickness of the lens frame 127.

[0067] Referring back to FIG. 12, a cover A 128 screwed to the body 115is fixed to the outer circumference of the imaging unit 113. A cover B129 is screwed to the cover A 128. The outer circumference of theimaging unit 113 is thus covered by two covers of the cover A 128 andcover B 129. This is intended to reinforce the fixation of the imagingunit 113 to the body 115 after the imaging unit is screwed firmly to thebody 115. An adhesive 130 is therefore injected into a space created bythe cover A 128, body 115, and imaging unit 113. Since two covers areused in combination, a desired position can be looked at accuratelyduring work. The adhesive 130 can be injected easily.

[0068] Moreover, as shown in FIG. 18, the signal cable 118 and powercables 120 are sandwiched between the cover B 129 and a fixture 131. Thetensile strengths in the axial direction of the cables are thusimproved. The fixture 131 is fixed to the cover B 129 by screws D 132.

[0069]FIG. 19 shows the system control unit 103 shown in FIG. 11. Thelight level adjustment knob 105 is located on a back end panel 133 ofthe control unit 104. The light level adjustment knob 105 is structurednot to jut out beyond the outer circumference 134 of the control unit104. Even if a worker nonchalantly places the endoscope at a site, theswitches including the light level adjustment knob 105 will hardly beflawed.

[0070] Moreover, the light level adjustment knob 105 may be, as shown inFIG. 20, located on the circumference of the control unit 104. In thiscase, the light level adjustment knob 105 will not jut out beyond theouter circumference 134.

[0071]FIG. 21 shows the outline of a light emitting diode 119 employedin the second embodiment. The light emitting diode 119 is made byputting a chip (light emitting device) 161 in a center dent of a ceramicpackage 160 and covering the chip portion with a silicon resin 162.

[0072] As mentioned above, in this embodiment, the light emitting diodes119 are fixed to the body 122 together with the substrate 121.Thereafter, the substantially transparent filler 124 is injected tofully cover the surroundings of the light emitting diodes 119 includingthe light emitting surfaces thereof. Since the tops of the lightemitting diodes 119 are covered with the filler 124, it is unnecessaryto place a transparent member in front of the light emitting diodes 119and to increase the outer diameter of the distal part. Moreover, thelight emitting diodes 119 can be not only protected to be blocked fromoutside but also left watertight.

[0073] The surroundings of the light emitting diodes and the front lightemitting surfaces thereof are covered with the filler in order torealize a watertight structure. This makes it unnecessary to ensure athickness large enough to support a transparent member used to attain awatertight state in the related art. The outer diameter of the distalpart can therefore be made smaller. Moreover, the employment of thefiller requires a smaller number of members than the employment of thetransparent member such as a glass. Besides, the price of the distalpart can be lowered.

[0074] Third Embodiment

[0075] The third embodiment is substantially identical to the secondembodiment. Only a difference will be described. The same referencenumerals will be assigned to identical components.

[0076] As shown in FIG. 22 to FIG. 24, a distal endoscope part 103 a inaccordance with the present embodiment is a distal part for a directviewing endoscope. An insertion unit including the distal endoscope part101 a consists of an optical adapter 140 and an endoscope body 141. Theoptical adapter 140 is mounted on the outer circumference of theendoscope body 141 and secured to a setscrew 142, which can rotate onlyin a circumferential direction, by means of attaching screws 143.

[0077] A plurality of light emitting diodes 119 is placed on thecircumference of an objective 144 in the optical adapter 140 with theobjective 144 as a center (see FIG. 23). The light emitting diodes 119are mounted on substrates 145 together with contact pins 146. Thesubstrates 145 are stowed in an adapter body 147 with the light emittingdiodes and contact pins united therewith. Thereafter, a substantiallytransparent filler 148 is injected to fully cover the light emittingdiodes 119 including even the tops thereof. The light emitting diodes119 are thus left watertight.

[0078] Power is supplied from the endoscope body 141 to the lightemitting diodes 119 in the optical adapter 140 over power cables 120.Specifically, power is delivered to the contact pins 146 in the opticaladapter 140 through contact receptacles 149 over the power cables 120.The power is then supplied to the light emitting diodes 119 via thesubstrates 145. A power supply member shall be composed of the contactreceptacles 149 and contact pins 146. The power supply member isisolated from the metallic member of the body 150 by insulators A 151,insulators B 152, and insulating tubes 153, and secured by screws 154(see FIG. 24).

[0079] Even in this embodiment, the filler 148 is injected to fullycover the light emitting diodes 119 including the tops thereof. Thelight emitting diodes 119 are thus left watertight. The same advantageas that provided by the second embodiment can therefore be provided.

[0080] In the present invention, it is apparent that a wide range ofdifferent embodiments can be constructed based on the invention withouta departure from the spirit and scope of the invention. This inventionwill be limited by the appended claims but not restricted by anyspecific embodiments.

What is claimed is:
 1. A distal endoscope part having a plurality oflight emitting diodes for supplying illumination light which is placedas an illuminating means on the outer circumference of an objectiveoptical system, wherein said plurality of light emitting diodes ismounted on a substrate and united therewith; and a sub-assembly made byuniting said plurality of light emitting diodes with said substrate isplaced on a plane containing the longitudinal axis of an insertion unitof an endoscope and its neighborhood.
 2. A distal endoscope partaccording to claim 1, wherein the surroundings of said plurality oflight emitting diodes are filled with a filler.
 3. A distal endoscopepart having an imaging means on which an optical image is projected viaan objective optical system and a plurality of light emitting diodes forsupplying illumination light which is placed as an illuminating means onthe outer circumference of said objective optical system, wherein saidplurality of light emitting diodes is mounted on a substrate and unitedtherewith; and a sub-assembly made by uniting said plurality of lightemitting diodes with said substrate is placed on a plane containing thelongitudinal axis of an insertion unit of an endoscope and itsneighborhood.
 4. A distal endoscope part according to claim 3, whereinthe surroundings of said plurality of light emitting diodes are filledwith a filler.
 5. A distal endoscope part having an imaging means onwhich an optical image is projected via an objective optical system andlight emitting diodes for supplying illumination light which are placedas an illuminating means on the outer circumference of said objectiveoptical system, wherein the surroundings of said light emitting diodesare filled with a filler.
 6. A distal endoscope part according to claim5, wherein said light emitting diodes irradiate said illumination lightin a direction perpendicular to the longitudinal axis of an insertionunit, and said optical image falls on said objective optical system inthe direction perpendicular to the longitudinal axis of said insertionunit owing to said illumination light irradiated from said lightemitting diodes.
 7. A distal endoscope part according to claim 5,wherein said light emitting diodes irradiate said illumination light ina direction of the longitudinal axis of said insertion unit, and saidoptical image falls on said objective optical system in the direction ofthe longitudinal axis of said insertion unit owing to said illuminationlight irradiated from said light emitting diodes.
 8. An endoscope havingan insertion unit that is inserted into a lumen, wherein the distal partof said insertion unit includes an objective optical system on which anoptical image falls and a plurality of light emitting diodes forsupplying illumination light which is placed as an illuminating means onthe outer circumference of said objective optical system, wherein saidplurality of light emitting diodes is mounted on a substrate and unitedtherewith; and a sub-assembly made by uniting said plurality of lightemitting diodes with said substrate is placed on a plane containing thelongitudinal axis of said insertion unit of said endoscope and itsneighborhood.
 9. An endoscope according to claim 8, wherein thesurroundings of said plurality of light emitting diodes are filled witha filler.
 10. An endoscope according to claim 8, wherein a light leveladjusting means used to adjust an amount of light emitted from saidplurality of light emitting diodes is located at the proximal end ofsaid insertion unit.
 11. An endoscope according to claim 10, wherein thesurroundings of said plurality of light emitting diodes are filled witha filler.
 12. An endoscope having an insertion unit that is insertedinto a lumen, wherein the distal part of said insertion unit includes anobjective optical system on which an optical image falls, a plurality oflight emitting diodes for supplying illumination light which is placedas an illuminating means on the outer circumference of said objectiveoptical system, and an imaging means on which said optical image isprojected via said objective optical system, wherein said plurality oflight emitting diodes is mounted on a substrate and united therewith;and a sub-assembly made by uniting said plurality of light emittingdiodes with said substrate is placed on a plane containing thelongitudinal axis of said insertion unit of said endoscope and itsneighborhood.
 13. An endoscope according to claim 12, wherein thesurroundings of said plurality of light emitting diodes are filled witha filler.
 14. An endoscope according to claim 12, wherein a light leveladjusting means used to adjust an amount of light emitted from saidplurality of light emitting diodes is located at the proximal end ofsaid insertion unit.
 15. An endoscope according to claim 14, wherein thesurroundings of said plurality of light emitting diodes are filled witha filler.
 16. An endoscope having an insertion unit that is insertedinto a lumen, wherein the distal part of said insertion unit includes anobjective optical system on which an optical image falls, light emittingdiodes for supplying illumination light which are placed as anilluminating means on the outer circumference of said objective opticalsystem, and an imaging means on which said optical image is projectedvia said objective optical system, and wherein the surroundings of saidlight emitting diodes are filled with a filler.
 17. An endoscopeaccording to claim 16, wherein a light level adjusting means used toadjust an amount of light emitted from said light emitting diodes islocated at the proximal end of said insertion unit.
 18. An endoscopeaccording to claim 16, wherein said light emitting diodes irradiate saidillumination light in a direction perpendicular to the longitudinal axisof said insertion unit, and said optical image falls on said objectiveoptical system in the direction perpendicular to the longitudinal axisof said insertion unit owing to said illumination light irradiated fromsaid light emitting diodes.
 19. An endoscope according to claim 18,wherein a light level adjusting means used to adjust an amount of lightemitted from said light emitting diodes is located at the proximal endof said insertion unit.
 20. An endoscope according to claim 16, whereinsaid light emitting diodes irradiate said illumination light in adirection of the longitudinal axis of said insertion unit, and saidoptical image falls on said objective optical system in the direction ofthe longitudinal axis of said insertion unit owing to said illuminationlight irradiated from said light emitting diodes.
 21. An endoscopeaccording to 20, wherein a light level adjusting means used to adjust anamount of light emitted from said light emitting diodes is located atthe proximal end of said insertion unit.